Themes between PSP, PS3, PSV and PS4 are incompatible with each other platforms. Packaging is different. File formats are incompatible (PSP and PSV using *.gim, while PSV and PS4 *.png but also in different sizes and with different deep bit). Meta data is/are incompatible. Everything is incompatible.
However, as everyone above already said, more or less, themes can be recreated using original assets. They will not work the same and they will not look the same but more or less similar, depend of author skills, taste and style direction.